Recent advances in heart surgery and cardiology have led to human heart transplantation and to the realization that the eventual solution to the problem of dealing with a failing heart may lie in the use of a man-made replacement device or pump.
At the present time, machines are being used in hospitals to bypass the natural heart and take over its function while surgery is being performed on the heart. Such machines are not constructed for use as cardiac replacement devices inside of the body, and up to the present time, no such means has been available, although research and development toward this end is underway.
The objective of this invention is, therefore, to provide a total cardiac replacement device or pumping unit which hopefully will advance the state of the art somewhat closer to the time when a man-made device can be successfully implanted in the body as a practical and permanent replacement for the natural heart which has failed. For such an event to become a reality, a large number of problems must be dealt with including the development of a small practical long-lasting power supply, creation of a sufficiently compact, durable and efficient pumping mechanism, and discovery of materials which are tissue-compatible, and the use of which device will maintain hemolysis within acceptable limits. Substantial progress is being made toward the solution of some of the above problems in the medical and engineering communities.
It is believed that the present invention is a significant advance in the art. More particularly, the invention embodies a pumping unit forming a total cardiac replacement device whose operation resembles the operation of the natural heart by providing a pulsatile flow of blood, a filling rate of ventricular sacs which is a function of right and left atrial pressure and volume, and an independent stroke volume for each ventricle sac depending on filling pressure within the sacs. In the device according to the several embodiments thereof, blood is contained within tissue compatible components and does not contact metallic parts.
Other features and advantages of the invention will become apparent during the course of the following detailed description.